1. Field of the Invention
This invention relates to transmission line connectors, specifically connectors for semi-rigid coaxial cables, and more particularly to connectors having an inner conductor support and are capable of providing a constant impedance connection for the signal path, including when the connectors are only partially engaged.
2. Description of Related Art
Connectors link the various conductors of transmission lines to equipment or other cables. A coaxial cable connector provides an electrical conductive contact between conductors of electricity in a coaxial cable; wherein the joint is of a type that may be readily made and broken, repeatedly by attachment and detachment of contact supporting structure on each conductor.
The connectors usually include a small projecting male center conductor and a corresponding female center conductor made to mechanically and electrically receive the male portion.
The center conductor portion of the connector is quite fragile and prone to damage. The center conductor portion can become damaged when, for example, the connector is misaligned during a connection. This is likely to happen during “blind-mate” connections, remotely located connections, and quick connect/disconnect applications. Generally, the center conductor is made of a bendable copper wire of finite diameter, having little or no mechanical support to resist bending or other forces. In typical coaxial connectors, the male portion of the center conductor projects and extends out beyond the outer conductor for insertion into the female portion. Thus, the center conductor tip of a coaxial cable connector is exposed and vulnerable to handling and deforming during insertion.
A coaxial cable or connector as identified above, has a characteristic impedance determined by the geometry of the cable or connector structure and the corresponding dielectric material between the conductors. The characteristic impedance may be represented by the formula:Z=138 (ε)−1/2 log(D/d), where,                Z is the impedance of the line;        D is the inner diameter of the outer conductor;        d is the outer diameter of the inner conductor; and        ε is the relative dielectric constant.        
Importantly, the connector must also exhibit this same impedance. Otherwise, signal disruption and reflections will degrade the signal quality due to the impedance mismatch. This is especially true in the higher frequency regimes, in applications where the signal frequency is on the order of 1 gigaHertz and higher.
Although the prior art has attempted in numerous ways to minimize the impedance mismatches that normally occur in connectors, there is no teaching or suggestion to strengthen the bendable center conductor or provide any form of structural support to the center conductor while keeping the impedance constant throughout the connector engagement.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a constant impedance connector that can maintain the constant impedance when the connector is partially or fully engaged while employing a support structure on the center conductor.
It is another object of the present invention to provide a coaxial connector center conductor that will not easily bend or deform during alignment or blind connection, and maintains constant impedance when mated with a corresponding female connector.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.